Term
| Lots of stuff fall on earth every year (about 20,000 meteorites) why do we find so few? |
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Definition
2/3 fall into the oceans
Lots fall into unpopulated areas. |
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Term
| Where do we find meteorites on earth? |
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Definition
Old dry locations
Africa
Australia
Antarctica |
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Term
| Why do we find meteorites on the mountains of Antarctica? |
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Definition
| When the ice butts up against the mountais, wind evaporates off the ice and uncovers the meteorites. |
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Term
| Where do meteorites come from? |
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Definition
Mars
Moon
The Asteroid Belt |
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Term
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Definition
Mostly basalt
They are ~1Byrs old and mars was the only planet still geologically active then so they must be from mars (venus' atmosphere is to thick for meteorites) |
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Term
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Definition
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Term
| How do we know meteorites come from the asteroid belt? |
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Definition
1. 1992 impact in new York, several people caught it on film and they worked out the trajectory started in the asteroid belt
2. The spectrum reflected off of the meteorites is the same as the spectrum reflected off the asteroids. |
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Term
| What are the types of meteorites? |
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Definition
Stoney: carbonaceous Chondrites, Ordinary Chondrites, and Achondrites
Story-Iron
Iron |
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Term
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Definition
| Objects that have not changed since the beginning of the solar system. |
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Term
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Definition
Carbonaceous= the background is made of carbon and looks black
Chondrites= the round spherres are called condrules.
Primitive objects 4.6Byrs
Found amino acids
Asteroids they are From must be undifferentiated and small.
1/4 of all meteorites |
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Term
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Definition
| The asteroid that the meteorite came from. |
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Term
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Definition
The building blocks of protiens
An important piece to life on earth.
Finding it on a meteorite means signs of life on an extra terrestrial object. |
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Term
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Definition
Have chondrules but they are broken up.
They have been heated in the past (lacking volatiles)
Not primitive
Asteroid was differentiated
Asteroid was larger so that it could be differentiated. |
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Term
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Definition
ROCKS all kinds
From the surface of a geologically active asteroid.
4.5Byrs so geologic activity on asteroids was LONG ago (makes sence because they are so small) |
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Term
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Definition
1% of meteorites
Rock (olivine) and iron
From geologically active/differentiated planets
From the margin between the core and the mantle. |
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Term
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Definition
5% of meteorites that hit earth 50% of meteorites we find- they stand out..
From the cores of asteroids
Have Widmanstatten patterns
Come from large differentiated asteroids. |
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Term
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Definition
Only get it on iron meteorites
When iron has lots of time to cool slowly in the core of an asteroid it gets this texture. |
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Term
| Describe the approximate size (in km), shape, density (in g/cm3), and moment-of-inertia, and age of the parent body of a carbonaceous chondrite. |
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Definition
very small
Density: 3.0 (g/cm3)
MOI: 0.40
Age: 4.6 Byrs |
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Term
| Describe the approximate size (in km), shape, density (in g/cm3), and moment-of-inertia, and age of the parent body of an Ordinary Chondrite. |
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Definition
slightly larger then carbonaceous
Density: ~3.3 g/cm3
MOI: ~0.39
Age: a little less then 4.6 Byrs |
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